Craft CMS may expose private assets through anonymous "generate transform" calls via transform URL

CVE-2026-33160 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Summary

An unauthenticated user can call assets/generate-transform with a private assetId, receive a valid transform URL, and fetch transformed image bytes.

The endpoint is anonymous and does not enforce per-asset authorization before returning the transform URL.

Details

Root cause:
- Anonymous endpoint accepts user-controlled asset reference.
- It creates and returns a transform URL for that asset without checking access rights.
- If the transform output is reachable, guest users can read content derived from private assets.

Who is impacted:

  • Installations where private source assets can be transformed and transform URLs are reachable.

Security consequence:

  • Anonymous users can obtain content derived from private assets without authentication.

Resources

https://github.com/craftcms/cms/commit/7290d91639e

Basic information

Type
reviewed
Severity
low
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-03-24 16:59:58 UTC
Updated
2026-03-25 21:00:13 UTC
GitHub reviewed
2026-03-24 16:59:58 UTC
NVD published
2026-03-24

EPSS Score

Score Percentile
0.04% 12.84%

CVSS Scores

Base score Version Severity Vector
2.7 4.0 —
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:L)
Limited confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:U)
Unreported: no public PoC, no reported exploitation, and no known simplification tools.

Identifiers

Type Value
GHSA GHSA-5pgf-h923-m958 ↗
CVE CVE-2026-33160 ↗

CWEs

CWE id Name
CWE-639 Authorization Bypass Through User-Controlled Key
CWE-862 Missing Authorization

Credits

  • GCXWLP (reporter)

Affected packages (2)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
composer craftcms/cms >= 5.0.0-RC1, <= 5.9.13 5.9.14 —
composer craftcms/cms >= 4.0.0-RC1, <= 4.17.7 4.17.8 —

References

cvelogic Threat Intelligence